Oral glutamine slows down whole body protein breakdown in Duchenne muscular dystrophy.
We determined whether glutamine has a protein anabolic effect in six 8-13-y-old boys with Duchenne muscular dystrophy. Children received a 5-h i.v. infusion of L-[1-13C]leucine and L-[2-15N]glutamine in the postabsorptive state on two consecutive days while drinking: 1) flavored water on one day, and 2) the same drink mixed with L-glutamine (800 micromol x kg[-1] x h[-1]), the other day. Oral glutamine administration was associated with an 8% decrease in leucine release from protein breakdown, from 116 +/- 5 to 107 +/- 6 micromol x kg(-1) h(-1) (p < 0.01), and a 35% decrease in leucine oxidation rate from 23 +/- 2 to 15 +/- 2 micromol x kg(-1) x h(-1) (p < 0.01), resulting in no change in the nonoxidative leucine disposal, an index of protein synthesis. Whole body glutamine exchange in plasma doubled from 321 +/- 22 to 623 +/- 24 micromol x kg(-1) x h(-1), p < 0.01, but glutamine from protein degradation and glutamine de novo synthesis both decreased (91 +/- 4 versus 84 +/- 5 micromol x kg(-1) x h(-1), p < 0.01, and 230 +/- 21 versus 163 +/- 25 micromol x kg(-1) x (h-1), p = 0.02, respectively). These data suggest that acute oral glutamine administration might have a protein-sparing effect in children with Duchenne muscular dystrophy, decreasing estimates of whole body protein degradation and glutamine de novo synthesis, therefore sparing nitrogen precursors.
Hankard
R G
RG
Nemours Children's Clinic, Jacksonville, Florida 32247, USA.
Hammond
D
D
Haymond
M W
MW
Darmaun
D
D
D000284:Administration, Oral; D000293:Adolescent; D002648:Child; D005973:Glutamine / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000627:therapeutic use*; D006801:Humans; D007201:Indicator Dilution Techniques; D007930:Leucine / Q000378:metabolism; D008297:Male; D009136:Muscular Dystrophies / Q000188:drug therapy* / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*
D011506:Proteins; D005973:Glutamine; D007930:Leucine